Google's three-year battle with the EU competition regulator could be coming to a close, according to the man in charge of the case – but he warned that other inquiries were on the horizon.

The European Commission opened an anti-trust investigation into Google in November 2010 after complaints from competitors, including alleged favourable treatment of it own products and services within searches.

More than a dozen companies, including Microsoft, the price comparison site Foundem and the German online mapping company Hotmaps, accused Google of squeezing them out of the market.

The internet giant's initial proposed remedies were rejected earlier this year after complaints from competitors, but yesterday the EU competition commissioner Joaquin Almunia said there had been "significant improvements" and that "we have reached a key moment in the case".

At a meeting of digital companies and lobbyists at the European Parliament in Brussels, Mr Alumnia said a legally binding agreement could be reached early next year. "With the significant improvements on the table, I think we have the possibility to work again and seek to find an effective solution," he said.

Google has agreed to give more screen space to competitors and display their logos within searches.

The search giant will also allow competitors to bid for prominence in search results based on specific phrases, rather than categories, allowing smaller rivals to compete.

A Google senior vice-president, Kent Walker, described the new proposals as a "difficult decision" for the company. The alternative to a legally binding commitment would be a fine, which analysts estimate could be as much as $5bn (£3.1bn).

Mr Almunia warned that the commission could still be forced to impose a fine if a trial of the new proposals was rejected by competitors.

Mr Alumnia also warned that Google face other antitrust cases were still being investigated, including its use of Motorola patents and aspects of the Android phone operating system.